In this case you should read the file line by line and then do what i showed you in a loop, like this:
Instead of the "echo" insert whatever you want to do with the value. Using "awk" or "sed" (or "perl" or whatever) for the same purpose will be slower because these programs have to be invoked while parameter expansion is done within the shell itself.
If your goal is not solely to produce a modified file (in this case "sed" is the best solution) but to do something inside the shell with the values thus generated you should do it like i told you.
Hi,
How would I get rid of lines having something else than numbers (such as tabs,white space, special characters, empty line, letters).
So I have big file with numers as follows:
12345678901
23456789012
32343678901
42345638901
52345678901
and I sometimes the file might contain some... (2 Replies)
just have a file
1:2333 2:-09393 ]3:45453 4:-09999 5:-09933 6:93939
question is to get output by removing colons as well as number before each colon (in bold)
2333 -09393 45453 -09999 09933 93939 (5 Replies)
Hi all,
Can I edit this script:
find . -type f | while read i;do && mv "$i" "${i//abc/}" ;done
so that it will not only take out abc from the filename but also take out any numbers that might be in the filename as well.
An example would be,
Input:
filename abc 2009.mov
Output:... (7 Replies)
How can I remove the numeric (1,2,3,4,5,etc.) in front of each line? The file look like this..
1CREATE OR REPLACE pROD (p_sc_id number,
2 p_snap_id number , p_sid number, p_halt varchar2 default 'N', p_a_nm varchar2 )
3 as
4 v_rtn number;
5
6 v_rtn... (3 Replies)
What am I doing wrong here? Or is this not possible?
A bug?
alias f='find . >found 2>/dev/null &'
f ; sleep 20 ; ls -l
-bash: syntax error near unexpected token `;' (2 Replies)
Hi guys,
This is my input
2735:<7001> 34 789 701 2
2774:<7001> 34 789 701 2
How to delete characters after colon :
Including colon : too ?
My output should... (3 Replies)
I have a file that has some text that looks like this
Some Text
1. More text
2. Different text
Final Text
I would like the remove the lines of text that start with the numbers.
Some Text
Final Text
I have tried to use cat file.txt | grep -Ev 1. >... (9 Replies)
Although i tried multiple option i couldn't find a way to get the rigt ouput.
Say i have the following data
cat file.txt
C request
C response
C request
C response
The output should look like (9 Replies)
The bash below executes and does find all the .bam files in each R_2019 folder. However set -x shows that the .bam extension only gets removed from one .bam file in each folder (appears to be the last in each). Why is it not removing the extension from each (this is $SAMPLE)? Thank you :).
set... (4 Replies)
Discussion started by: cmccabe
4 Replies
LEARN ABOUT CENTOS
shell-quote
SHELL-QUOTE(1) User Contributed Perl Documentation SHELL-QUOTE(1)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$SHELL -c". This doesn't work as intended:
ssh host touch 'hi there' # fails
It creates 2 files, hi and there. Instead, do this:
cmd=`shell-quote touch 'hi there'`
ssh host "$cmd"
This gives you just 1 file, hi there.
process find output
It's not ordinarily possible to process an arbitrary list of files output by find with a shell script. Anything you put in $IFS to
split up the output could legitimately be in a file's name. Here's how you can do it using shell-quote:
eval set -- `find -type f -print0 | xargs -0 shell-quote --`
debug shell scripts
shell-quote is better than echo for debugging shell scripts.
debug() {
[ -z "$debug" ] || shell-quote "debug:" "$@"
}
With echo you can't tell the difference between "debug 'foo bar'" and "debug foo bar", but with shell-quote you can.
save a command for later
shell-quote can be used to build up a shell command to run later. Say you want the user to be able to give you switches for a command
you're going to run. If you don't want the switches to be re-evaluated by the shell (which is usually a good idea, else there are
things the user can't pass through), you can do something like this:
user_switches=
while [ $# != 0 ]
do
case x$1 in
x--pass-through)
[ $# -gt 1 ] || die "need an argument for $1"
user_switches="$user_switches "`shell-quote -- "$2"`
shift;;
# process other switches
esac
shift
done
# later
eval "shell-quote some-command $user_switches my args"
OPTIONS --debug
Turn debugging on.
--help
Show the usage message and die.
--version
Show the version number and exit.
AVAILABILITY
The code is licensed under the GNU GPL. Check http://www.argon.org/~roderick/ or CPAN for updated versions.
AUTHOR
Roderick Schertler <roderick@argon.org>
perl v5.16.3 2010-06-11 SHELL-QUOTE(1)